Adult myopia onset and progression is a common clinically observed entity. It has implications for students undergoing academic training for professions that set uncorrected visual acuity standards, and careful quantification of the prevalence and severity of adult myopia progression will prove to be vital in the emerging era of refractive surgical correction. The phenomenon of adult myopia progression has not, however, been well quantified in large study populations. We propose to analyze an existing database from the research clinic of CIBA Vision in Duluth, Georgia. It is comprised of 411 myopes that have been followed for an average of 7.5 years (range 4 to 15 years). The sample is unique in that it includes patients in the fourth decade of life. Males and females are represented in roughly equal proportions. Patients present to the database through annual eye examinations required to continue their participation in contact lens studies that give them free contact lenses, rather than because of decreasing distance visual acuity and increasing myopia. The proposed project will examine this existing database in order to: 1. Compare linear and non-linear models of adult myopia progression; 2. Investigate potential risk factors (age, gender, initial refractive error, and occupation) for high rates of adult myopia progression; and 3. Provide information for evaluating entry criteria and estimating sample size in planning longitudinal studies and/or clinical trials of adult myopia onset and progression.